Imaging method and materials

ABSTRACT

WHERE M is a heavy metal ion, and D and preferably D&#39;&#39; are photographic developer structures. Actinic radiation for the said coordinate structures reduces the metal ions and partially oxidizes the fragments D, D&#39;&#39;, whereby image development of members sensitized with said coordinate structures can be effected by chemically disrupting the NH-C bonds.   Imaging methodology and materials are disclosed utilizing cyanine dye coordinate structures of the type:

United States Patent 91- Young lMAGlNG METHOD AND MATERIALS [76}Inventor: James E. Young, 50 Larchwood Dr.,

Pittsford, N.Y. 14534 [22] Filed: May 26, 1972 [21] Appl. No.: 257,289

Related 1.1.8. Application Data [63} Continuation-in-part of Ser. No.52,981, July 7,

1970, abandoned.

[ 52] US. Cl. 96/48 R, 96/48 HD, 96/67, 96/76 R [51] Int. Cl G03c 5/24[58] Field of Search 96/1 14.6, 2, 48 HD, 96/48 R, 114.1, 67, 76 R [56]References Cited UNITED STATES PATENTS 3,692,526 9/1972 Ulbing 96/108Primary Examiner-Norman G. Torchin Assistant Examiner-Alfonso T. SuroPico Attorney-Stefan J. Klauber [57] ABSTRACT Imaging methodology andmaterials are disclosed uti' lizing cyanine dye coordinate structures ofthe type:

8 Claims, No Drawings 1i IMAGING METHOD AND MATERIALS This applicationis a continuation-in-part of my copending application, Ser. No. 52,981,filedJ uly 7,1970 now abandoned.

This invention relates generally toimaging technology, and morespecifically relates to-methods and materials for photographic imagingof lightpatterns.

In conventional black and white photographic methodology, photosensitivecompoundstypically silver salts are present ina light sensitiveemulsion, and following exposure tothe light patterntobe recordeddevelopment of the latent image isachieved' through use of an externaldeveloping;agent',.whi'ch agent upon application to the said emulsioneffects a reductionoxidation reaction at exposed pointstherein to reducethe said silver to-its metallic form.

Although the conventional methodology set forth is in mostwidespreaduse, there are. certaininherent'deficiencies in suchprocessesw-hichyet limittheir usefulness. Such deficiencies principallyderivefrom the use therein of the aforesaid external developing'agents.Because of the requirement'toemploy these agents to develop the latentphotographic image, relatively sophisticated techniques and lengthyprocedures need be used to develop conventional exposedfilm,andin-consequence the vast bulk ofsuch processingis indeed performed byindustrial laboratories ortherlikewhich possess the sophisticatedexpertise. desirable for: assuring uniform quality indevel'oped5products. Thehigh'volume industrial-type processor 'issimilarly favored in comparison to the amateur or small scale processorin.

that the shelf life of these external'developing agents is limited andthe freshness of reagentsis an important consideration inassuring highquality results. i

The use of the aforementioned externaldeveloping agents has yet anotherimportantrdetrimental effecton image quality. In. particular it isnecessary during the development process for the said: agentsto diffusethrough the sensitizedlayer to'thesitus' of the-latentim age, and it isoftenfound' in consequencetthat' resolving properties of the imaginglayer.- are'adversely affected by such diffusion process.

In accordance with theforegoing; itmay be-regarded.

as an object of the presentinvention, to-provide processes and materialswhich vastly simplify the processing techniques for developing. imagesin an exposed photographic member,

It is a further object of the. presentinvention, to provide imagingmethods-and'materials which-enable. development of latent images inexposedmembers-by simple heat, infra-red or radiant: energy processingtechniques, or by simple treatment:of'saidsmemberwith,

a buffered aqueous alkaline. solution.

It is another object of the: present-invention, to provide animagingmember of'high lightsensitivity and displaying excellentimageresolution.

Now in accordance withthepresentrinvention, the foregoing objects, andothers-aswill' become apparent in the course of the.ensuingspecification;.are achieved in an imaging system based'upon useofcyaninedye coordinate structures of the general'type:

where n isan integer, M is a'heavy metal ion such as silver (which ionmay also be thus complexed as the metal halide), and D and preferably Dare photographic developer structures-such as a para amino phenol, somein their oxidized form, which form with the guanidine-type C=N NEstructure a cyanine dye. Where both D and D are developer structures, Dand'D need not be identical. D may, for example, be of adifferenttype toprovide a mixture of developing agents, thereby producing asuper-additive effect in the developingprocess.

Theentire. structure (1) is effectively a cyanine dye sensitizer andwhen light of appropriate wavelength. (actinic radiation)-strikes thestructure (1) and is absorbed; the dye molecule donates electrons to themetal ion, reducing such: ions andpartiall'y' oxidizing the reducingagents represented by D andinpreferable embodiments by D. In a typicalprocess, M is silver and followinglight exposureheat and/or a bufferedal kaline solution is applied to" the exposed image. The heat (of theorder of to2007C) or alkalinesolution (pH of the order of 10 to 13disrupts the NH-C bonds in the said actas photographic developers orreducing agents. ln

the. structure (.1) at-least the fragments Dwillconstitutesuchadeveloper agent; the D fragment need not'in general be a developingagent, butmust only be capable of forming a cyanine dye withthe'guanidine type 7 NH- portion of structure (1") and b''sess'theadditionalcharacteristic that itnot dye couple with the fragments ofoxidized developing. agent D released from" said guanidine-typestructure. In preferable embodiments of the invention, however, D willin fact be a developing agent: preferably thus, D will be a para aminophenol or para phenylene diamine while D will be selected from theoxidized para dihydroxyv benzenes. Representative structures for theseorganic salts include:

NH: or OH type H N(CH=CH)nNH NH: NH; IIIHR OH: or NH:

CH3 or NH: CHa

Typical structures for D Type HO(CH=CH ),,OH (in their oxidized state)OH OH Representative structure 2), above, is seen to be of the generalform:

4 N Rz N Rz 7 Provided only that the groups corresponding to D, D instructure (1 are photographic developers, the structure (4) can be evenfurther generalized to:

I] I I 0 JLOR,

Cl, Br,

--SO H, -NO The dyes used herein are by virtue of their dual purposemodified cyanines. Dyes of this general type are elucidated in theliterature and the procedures for synthesis of compounds of this typeare well-known to those skilled in the art. Many current processes, forexample, for the formulation of cyanine dyes use condensation typereactions. These reactions, shown in Mees, C.E.K., The Theory of thePhotographic Process, The Macmillan Co., New York, 1955,: utilizeanactive hydrogen on one reactant and an active negative atom (halogen,cyano, alkyl or aryl mercapto', alkoxy,

anilino, or acetanilido) on the other reactant. Condensing agents areused as scavengers and to shift'the reaction equilibrium in the desireddirection. The intermediates used in the preparation of conventionalsensitizing dyes, and the condensing agents, including their preparativeprocedures, are discussed in Glafkides, P., Photographic Chemistry, Vol.I and 11, Fountain Press, London, 1960 starting on page 753.

Typically, the dyes described in this patent application can be preparedby the two following examplary approaches, depending upon thesubstituents in the dye intermediates: I

a. By condensation of appropriately substituted guanidines withintermediates containing negative active atoms in the desired positions:and

b. by formation of the appropriately substituted guanidine structure insitu via the reaction of the substituted carbodiimide with amino group slocated in the dye intermediate.

Coordinate structures such as l 2, and 3, may therefore, for example,pursuant to approach a as set forth above, be prepared by the followingtype of flow-process:

Substituted Disubstituted Disubstituted giggli Thiourea GuanidinoReaction I Reaction 11 Negative Atom Sensitive Substituted DyeIntermediate Compound m nlil In many instances the substituted aromaticamine and the Negative Atom Substituted Intermediate are commerciallyavailable compounds.

The flow process above set forth is now illustrated in the course ofpreparing the structure (3):

EXAMPLE 1 1. Preparation of N,N bis (4-hydroxyphenyl) thiourea:

In a 300 ml balloon flask, place 50 ml (39.57g) anhydrous methylalcohol, 6 ml (7.6g) carbon disulfide (Baker 9172), 21.8g p-aminophenol(Eastman Kodak P362), and 1.5g Potassium Hydroxide (Baker 3140). Anexothermic reaction may occur which will require cooling to contain thereactants. After the initial reaction subsides, attach electric heatingmantle and water cooled condenser, reflux the mixture for 8 hours.Distill off the excess alcohol and CS Wash residue with warm water toremove residual KOH and unreacted paminophenol. Filter, wash with warmwater, and dry. Purify by recrystalization, desolving the residue underreflux in boiling rectified spirits (ethanol). Filter in heated funnelif the solution is not clear. Add hot-water until the solution becomescloudy, cool, and filter. Additional information respecting thisreaction 1 may be found at:

Fusion, Organic Chemistry, John Wiley & Sons lnc., New York 1942 p.415;Brewster, Organic Chemistry, Prentice-Hall, New York, 1948 p.553; Smith,The Chemistry of Open Chain Organic Nitrogen Compounds, vol 1, W.A.Benjamin lnc., New York' 1965 p.276; Wertheim, Practical OrganicChemistry A Laboratory Manual, McGrawHill, New York, 1953 p.642.

EXAMPLE 2 11 1 Preparation of N,N' bis (4-hydroxyphenyl) guanidineEquations:

Anhydrous In a 500 ml two necked balloon flask, place 100 ml (87.9g) drybenzene (BA 9154), 20g anhydrous magnesium sulfate (BA 2506), 44gmercuric oxide (BA 2620), a gas dispersion tube with fritted disc orcylinder is introduced into the mixture through one neck of the flask.Anhydrous ammonia gas is allowed to bubble through the mixturesaturating the solvent. Add 26g of N,N bis (4-hydroxphenyl) thiourea(from preparation 1) andinstall a water cooled condenser in the otherneck of the flask. Continue the'flow of ammonia gas. Attach an electricheating mantle and reflux the mixture for 6-8 hours with continous flowof ammonia. Note: the reaction mixture must be saturated at all timeswith ammonia gas as the intermediate carbodiimide will, if allowed,react with the hydroxyl groups reducing the yield of guanidine. Filterto remove sulfides and drying agent, distill off excess benzene, anddry. Purify by recrystallization from dry benzene. Additionalinformation respecting this reaction 11 may be found at:

Kurzer, Advances in the Chemistry of Carbodiimides, Chemical Reviews,vol. 67, No. 2, 1967 p.1 18; Bocharov, B.V., Progress in the Chemistryof the Carbodiimides, Russian Chemical Reviews, No. 3, March 1965, p.215; Smith, The Chemistry of Open Organic Nitrogen Compounds, vol. 1,WA. Benjamin lnc., New York, 1965 p.278; 1.G. Farbenindustrie Akt.-Ges.,German Pat. No. 481,994 (1926); Frdl., 16, 2516 (1931 1.G.Farbenindustrie Akt.-Ges., German Pat. No. 550,571 (1 927); Frdl., 17,310 (1932); Joshua, C.P., Indian Chem. Soc., 37, 621 (1960);Macholdt-Erdniss, J. Chem. Ber., 91, 1992 (1958); Silesia, German Pat.No. 456,854 (1925); Frdl., 16, 313 (1931);Weith, W.,

Chem. Ber., 7, 1303 (1874).

EXAMPLE 3 III Guanidine synthesis of a Merocyanine dye:

Condensation product of N,N bis (4- hydroxyphenyl) guanidine and2,5-dichloro-pbenzoquinone Equations:

In a 500 ml balloon flask, mix 100 ml (78.9g) anhydrous methanol, 24.3gN,N' bis (4-hydroxyphenyl) guanidine (from preparation [1), 8.9g2,5-dichloro-pbenzoquinone (EK 4410), 6g Magnesium oxide (BA 2477).Attach water cooled condenser, electric heating mantle, magneticstirring unit, and reflux the mixture for 2 hours. Filter to removesolids, distill off alcohol, wash residue with distilled water and dry.Purify by recrystallization from dry ethanol.

The formation of silver or silver halide salts of these dyes follow theconventional methods currently in use in the manufacture of silverhalide film. These processes involve the introduction of silver nitrateinto the mixture and subsequent introduction of soluble halide salts(Kl, KBr, KCl, NaI, NaBr, NaCl) followed by washing with water.

Additional information respecting this reaction III may be found at:

LG. Farbenindustrie, BIOS l482,p. 23 (PB86136); LG. Farbenindustrie, ibidi, p.26; Glafkides, Piere, Photographic Chemistry, Fountain Press,London 1958 Chapter XXVIII pp. 298-326. Omitting, for purposes ofsimplification, the complexed heavy metal ion such as silver we mayillustrate by structure (4), the manner in which stress introduced byheat or alkaline conditions effects fracture of the guanidine-like /C=NNH group R2 N 3 i NH \NR2 IX C:N- Heat or alkaline NI-I conditions Thedotted lines in (6) represent the characteristic manner in which thesaid guanidine-like group fractures, and it is thus evident fromequation (6) why structures such as (4) can serve as color sensitizer,sensitive media, and developing agent, without the need for conventionaldevelopment solutions.

In accordance with the present invention, the photosensitive layerutilized on an imaging member will typically include silver ion derivedfrom AgNO or AgX (Br, Cl, 1), a hygroscopic agent, a light sensitivestructure of the type (1), and a binder which preferably will be otherthan gelatin; e.g., polyvinyl alcohol or other permeable syntheticplastic. The said formulation is typically coated upon a plastic orbaryta coated paper substrate.

In accordance with the invention, processing of members thus prepared,is typically a simple three-step process involving: (1) developing byconvenient heating means, including, e.g., radiant heat (such heatingtypically raising the member to a temperature of the order of to 200C.)and/or treating with buffered alkaline water (pH of the order of 10 to13); (2) wash-- ing and stopping; and (3) fixing, e.g., withconventional silver solvent hypo.

While the present invention has been particularly set forth in terms ofspecific embodiments thereof, it will be .appreciated in view of theinstant disclosure, that numerous variations upon the present inventionare now enabled to those skilled in the art, which variations are yet,in propriety, within the scope of the instant teaching. Accordingly theinvention is to be broadly construed, and limited only by the scope andspirit of the claims now appended hereto.

1 claim: 1. A method for photographic imaging, comprising: a. exposingto a light pattern a sensitized layer containing cyanine dye coordinatestructures of the type:

where n is an integer, M is a silver ion, at least D is a photographicdeveloper structure, and D is a structure'which does not dye couple withoxidized fragments D split from said dye coordinate structure, actinicwavelengths present in said light act- 7 ing to reduce said metal ionsand partially oxidize at least D;

b. disrupting the chemical bonds joining said developer structures andamino group to said dye, to enable image development at points in saidlayer struck by said light; and

c. removing unreacted metal ion and metal complexes from said layer.

2. A method in accordance with claim 1 wherein D is further aphotographic developer structure, said light acting in addition topartially oxidize D.

3. A method in accordance with claim 2, wherein D is selected from thegroup consisting of para amino where n is an integer, M is a silver ion,at least D is a photographic developer structure, and D is a structurewhich does not dye couple with oxidized fragments D split from said dyecoordinate structure, said dye being chosen to be sensitive to saidlight, actinic wavelengths present in said light acting to reduce saidmetal ions and partially oxidize at least D, whereby disruption of thechemical bonds joining said developer structures and amino groups tosaid dye enables image development at points in said layer struck bysaid light.

7. A member in accordance with claim 6 wherein D is further aphotographic developer structure, said light acting in addition topartially oxidize D.

8. A member in accordance with claim 7, wherein D is selected from thegroup consisting of para amino phenols and para phenylene diamines, andD is an oxidized para dihydroxy benzene.

2. A method in accordance with claim 1 wherein D'' is further aphotographic developer structure, said light acting in addition topartially oxidize D''.
 3. A method in accordance with claim 2, wherein Dis selected from the group consisting of para amino phenols and paraphenylene diamines, and D'' is an oxidized para dihydroxy benzene.
 4. Amethod in accordance with claim 1, wherein said chemical bonds aredisrupted by treating said layer with an aqueous alkaline solution.
 5. Amethod in accordance with claim 1, wherein said chemical bonds aredisrupted by heating said layer.
 6. A member for photographic recordingof a light image pattern, comprising: a. a support substrate; and b. abinder layer coated upon said substrate containing cyanine dyecoordinate structures of the type:
 7. A member in accordance with claim6 wherein D'' is further a photographic developer structure, said lightacting in addition to partially oxidize D''.
 8. A member in accordancewith claim 7, wherein D is selected from the group consisting of paraamino phenols and para phenylenE diamines, and D'' is an oxidized paradihydroxy benzene.